If we are running late for a meeting, we'll blame it on public transport. If someone else is running late for a meeting with us, we'll blame it on their poor time-keeping. The fundamental attribution error we usually make is to assign external reasons for our own behaviour, but internal motives to other people.

The halo effect

Studies have found we are far kinder judges of other people if we find them attractive. Although there is no proven correlation between beauty and any other ability or personality trait, we tend to believe that attractive people are kinder and more intelligent than their less photogenic counterparts.

Height is also significant, especially in our judgment of men. Researchers found that a person's height influences how capable and intelligent we think they are. Taller men tend to be perceived as authoritative and clever. One study showed that the average earnings of British men increases by 2.6% with every extra inch of height, regardless of career choice.

The confirmation bias

If we hold a particular belief about someone, we will look for evidence that supports our theory while conveniently ignoring any facts that don't fit. If we believe that someone is lazy, we will spend more time thinking about and discussing the times they didn't wash up than all the times they may have emptied the bins.

Implicit association

Researchers have studied how we make mental connections between certain positive and negative words and pictures of different people - for example, old or young, white or black, male or female - betraying racism, sexism and other stereotypes

The "just world" phenomenon

We tend to believe that people "get what they deserve". So strong is our need to believe in the moral order of the universe that we may look for evidence that a victim of a crime had done something to warrant their bad luck.

The "black sheep" effect

We are harsher critics when we are judging people who we perceive as belonging to the same group as us if we think they have acted in a way that might harm the group. This bias allows us to protect the group at the expense of the "black sheep".